- Slang One that is uncontrolled and therefore poses danger: "[His] bloopers in the White House seem to make him . . . a political loose cannon” ( Tom Morgenthau).
- a cannon that breaks loose during struggle or a storm and results in really serious problems for the ship as well as its staff
- an uncontrolled or unpredictable one who causes damage to their very own faction, political celebration etc.
- someone who is expected to do a certain task but that is unmanageable and dangerous
- To act you might say such as for example to cause injury to ones own faction, governmental party etc.
Sentence for "loose cannon"
Urban Dictionary for "loose cannon"